Home → Tests → HbA1c
HbA1c (Glycated Hemoglobin) Test
✅ Up to date🔬 Evidence: StrongEndocrine & Metabolism
Diğer adları: A1c, A1c test, Glycated hemoglobin
⚠️
Discuss your test results with your doctor. This page is for informational purposes only and does not provide a diagnosis.
⚡ Key Facts
• Measures your average blood sugar level over the past 2–3 months
• Used in diabetes assessment and monitoring
• No fasting required
• Normal: <5.7% | Prediabetes: 5.7–6.4% | Diabetes: ≥6.5%
🧪 What Does This Test Measure?
The HbA1c test measures glycated hemoglobin to reflect average blood sugar levels over the past 2–3 months, without requiring fasting.
📋 Why Is It Ordered?
Used in diabetes assessment and monitoring. It may also be used in prediabetes screening and long-term glycemic follow-up.
🔧 Preparation
No fasting is required for the HbA1c test. It can be done at any time of day.
📊 Reference Ranges
Normal: <5.7% | Prediabetes: 5.7–6.4% | Diabetes: ≥6.5%
⚠️ These thresholds may vary depending on the method used, the laboratory, and the clinical context. Discuss your results with your doctor.
⬆️ High Values
Elevated HbA1c may be associated with diabetes, prediabetes, or persistently high blood sugar levels.
⬇️ Low Values
Low HbA1c may be associated with certain types of anemia, liver disease, frequent hypoglycemia, or recent blood loss. It should not be interpreted without clinical context.
⚙️ What Can Affect Results?
Certain conditions may make HbA1c less reliable as a reflection of actual blood sugar levels: iron deficiency anemia, hemoglobin variants, kidney disease, pregnancy, recent blood transfusion.
🔬 Evidence Summary
Strong evidence: 3 guidelines, 1 systematic review/meta-analysis, 2 clinical trials, and 2 reviews.
📚 Most Important Studies on This Topic
✅ Key Takeaways
💡
What you learned: HbA1c reflects your average blood sugar over 2–3 months. If your result is 5.7% or above, it may warrant further evaluation with your doctor.
⛔
A single HbA1c result cannot diagnose diabetes on its own. Clinical context and confirmatory testing are needed.
🔬 Sources Used on This Page
7 sources · Most recent publication: 2026📋
Guideline
Expert society and guideline recommendations
2
sources
📊
Systematic review / meta-analysis
Combined analysis of multiple studies
1
source
🔬
Clinical trial (RCT)
Controlled research conducted in humans
2
sources
📖
Review
Comprehensive topic evaluation
2
sources
Overall assessment: Evidence level for this topic is strong. This page is supported by 2 guidelines, 1 systematic review/meta-analysis, 2 clinical trials, 2 reviews.
📝 Questions to Ask Your Doctor
Be prepared for your appointment. Add questions to your list.
📋 References
[PMID: 41358893] Diagnosis and Classification of Diabetes: Standards of Care in Diabetes 2026. Diabetes Care, 2026.
[PMID: 27398023] Significance of HbA1c Test in Diagnosis and Prognosis of Diabetic Patients. Biomarker Insights, 2016.
[PMID: 24205486] HbA1c: a review of analytical and clinical aspects. Clin Chem Lab Med, 2013.
[PMID: 22115901] Intensive glycaemic control for patients with type 2 diabetes: systematic review with meta-analysis and trial sequential analysis of randomised clinical trials. BMJ, 2011.
[PMID: 26158184] Use of Glycated Haemoglobin (HbA1c) in the Diagnosis of Diabetes Mellitus: Abbreviated Report of a WHO Consultation. WHO, 2011.
[PMID: 18539917] Effects of intensive glucose lowering in type 2 diabetes. NEJM, 2008.
[PMID: 18539916] Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. NEJM, 2008.
Last reviewed: 3/24/2026
Next review: 3/24/2027
🔗 Related Topics
⚖️ This page does not replace medical advice. Make treatment decisions with your doctor.
Content is based on scientific studies indexed in PubMed and current clinical guidelines.
Content is based on scientific studies indexed in PubMed and current clinical guidelines.